Carborization of 321 Stainless

Guest,

Carburizing is the addition of carbon to the surface of low-carbon steels at temperatures generally between 850 and 950°C, at which austenite is the stable (face-centered-cubic) crystal structure.

Case hardening is accomplished when the high-carbon surface layer is quenched to form martensite (with a tetragonal crystal structure), so that a high-carbon martensitic case with good wear and fatigue resistance is superimposed on a tough, low-carbon steel core.

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I do not know the specifics regarding 321 SS (e.g., the eutectoid temperature), but I think you can obtain this information for a fee, by purchasing a paper entitled "THE CARBURIZATION OF FOUR AUSTENITIC STAINLESS STEELS" from the National Technical Information Services. (http://www.ntis.gov/) - (Document Accession Number : AD0694511).

The study evaluated carburization of 304,316,321,and 347 SS over the temperature range of 730C to 1040C, and included time and temperature carburization occurrence diagrams.

See the Abstract here:

(http://stinet.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=AD0694511)

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Just my $0.02.